1
|
Nagano R, Fujii S, Hasegawa K, Maeda H, Kiyoshima T. Wnt signaling promotes tooth germ development through YAP1-TGF-β signaling. Biochem Biophys Res Commun 2022; 630:64-70. [PMID: 36150241 DOI: 10.1016/j.bbrc.2022.09.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 08/09/2022] [Accepted: 09/02/2022] [Indexed: 11/25/2022]
Abstract
Tooth germ development involves continuous and sequential steps with reciprocal interactions between odontogenic epithelium and the adjacent mesenchyme. Several growth factors, including Wnt, are essential for tooth germ development. Molecular mechanisms underlying Wnt/β-catenin-regulated tooth germ development are poorly understood. In tooth germ rudiments culture, we recently demonstrated that Semaphorin 3A (Sema3A), an axonal guidance factor, stimulation reversed Wnt/β-catenin signaling-dependent decreased cell proliferation but did not completely rescue the morphological anomalies of tooth germ, suggesting that an uncharacterized signaling pathway may be essential in Wnt/β-catenin signaling-dependent tooth germ development. Herein, an enrichment analysis using DNA microarray data, which was obtained in our previous research, revealed that Wnt/β-catenin signaling negatively regulates YAP1 and/or TGF-β signalings. In odontogenic epithelial cells and tooth germ rudiments, Wnt/β-catenin signaling activation reduced YAP1 expression, thereby suppressing YAP1 and TGF-β signalings sequentially. Additionally, YAP1 signaling induced TGF-β2 expression to promote TGF-β signaling in the cells. Finally, Wnt/β-catenin signaling-dependent disorganized tooth germ development, in which YAP1 signaling was suppressed, was reversed by TGF-β stimulation. These results suggest that Wnt/β-catenin signaling contributes to the tooth germ development through YAP1-TGF-β signaling.
Collapse
Affiliation(s)
- Ryoko Nagano
- Laboratory of Oral Pathology, Division of Maxillofacial Diagnostic and Surgical Sciences, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan; Department of Endodontology and Operative Dentistry, Division of Oral Rehabilitation, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Shinsuke Fujii
- Laboratory of Oral Pathology, Division of Maxillofacial Diagnostic and Surgical Sciences, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan; Dento-craniofacial Development and Regeneration Research Center, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan.
| | - Kana Hasegawa
- Laboratory of Oral Pathology, Division of Maxillofacial Diagnostic and Surgical Sciences, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Hidefumi Maeda
- Department of Endodontology and Operative Dentistry, Division of Oral Rehabilitation, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Tamotsu Kiyoshima
- Laboratory of Oral Pathology, Division of Maxillofacial Diagnostic and Surgical Sciences, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| |
Collapse
|
2
|
Alotaibi RN, Howe BJ, Moreno Uribe LM, Ramirez CV, Restrepo C, Deleyiannis FW, Padilla C, Orioli IM, Buxó CJ, Hecht JT, Wehby GL, Neiswanger K, Murray JC, Shaffer JR, Weinberg SM, Marazita ML. Multivariate GWAS of Structural Dental Anomalies and Dental Caries in a Multi-Ethnic Cohort. FRONTIERS IN DENTAL MEDICINE 2022; 2:771116. [PMID: 36267138 PMCID: PMC9581442 DOI: 10.3389/fdmed.2021.771116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2023] Open
Abstract
Odontogenesis is a complex process, where disruption can result in dental anomalies and/or increase the risk of developing dental caries. Based on previous studies, certain dental anomalies tend to co-occur in patients, suggesting that these traits may share common genetic and etiological components. The main goal of this study was to implement a multivariate genome-wide association study approach to identify genetic variants shared between correlated structural dental anomalies and dental caries. Our cohort (N = 3,579) was derived from the Pittsburgh Orofacial Clefts Study, where multiple dental traits were assessed in both the unaffected relatives of orofacial cleft (OFC) cases (n = 2,187) and unaffected controls (n = 1,392). We identified four multivariate patterns of correlated traits in this data: tooth agenesis, impaction, and rotation (AIR); enamel hypoplasia, displacement, and rotation (HDR); displacement, rotation, and mamelon (DRM); and dental caries, tooth agenesis and enamel hypoplasia (CAH). We analyzed each of these four models using genome-wide multivariate tests of association. No genome-wide statistically significant results were found, but we identified multiple suggestive association signals (P < 10-5) near genes with known biological roles during tooth development, including ADAMTS9 and PRICKLE2 associated with AIR; GLIS3, WDR72, and ROR2 associated with HDR and DRM; ROBO2 associated with DRM; BMP7 associated with HDR; and ROBO1, SMAD2, and MSX2 associated with CAH. This is the first study to investigate genetic associations for multivariate patterns of correlated dental anomalies and dental caries. Further studies are needed to replicate these results in independent cohorts.
Collapse
Affiliation(s)
- Rasha N. Alotaibi
- Dental Health Department, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia
- Center for Craniofacial and Dental Genetics, Department of Oral and Craniofacial Sciences, School of Dental Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Brian J. Howe
- Department of Family Dentistry, College of Dentistry, University of Iowa, Iowa City, IA, USA
- The Iowa Center for Oral Health Research, College of Dentistry, University of Iowa, Iowa City, IA, USA
| | - Lina M. Moreno Uribe
- The Iowa Center for Oral Health Research, College of Dentistry, University of Iowa, Iowa City, IA, USA
- Department of Orthodontics, School of Dentistry, University of Iowa, Iowa City, IA, USA
| | | | | | | | - Carmencita Padilla
- Department of Pediatrics, College of Medicine, University of the Philippines, Manila
| | - Ieda M. Orioli
- Department of Genetics, Institute of Biology, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Carmen J. Buxó
- School of Dental Medicine, University of Puerto Rico, San Juan, Puerto Rico
| | - Jacqueline T. Hecht
- Department of Pediatrics, University of Texas Health Science Center at Houston, Houston, Texas, TX, USA
| | - George L. Wehby
- Department of Health Management and Policy, College of Public Health, University of Iowa, Iowa City, IA, USA
| | - Katherine Neiswanger
- Center for Craniofacial and Dental Genetics, Department of Oral and Craniofacial Sciences, School of Dental Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Jeffery C. Murray
- Department of Pediatrics, Carver College of Medicine, University of Iowa, Iowa City, IA, United States
| | - John R. Shaffer
- Center for Craniofacial and Dental Genetics, Department of Oral and Craniofacial Sciences, School of Dental Medicine, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Human Genetics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA
| | - Seth M. Weinberg
- Center for Craniofacial and Dental Genetics, Department of Oral and Craniofacial Sciences, School of Dental Medicine, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Human Genetics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA
| | - Mary L. Marazita
- Center for Craniofacial and Dental Genetics, Department of Oral and Craniofacial Sciences, School of Dental Medicine, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Human Genetics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA
| |
Collapse
|
3
|
Zhang H, Zhan Y, Zhang Y, Yuan G, Yang G. Dual roles of TGF-β signaling in the regulation of dental epithelial cell proliferation. J Mol Histol 2020; 52:77-86. [PMID: 33206256 DOI: 10.1007/s10735-020-09925-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Accepted: 10/27/2020] [Indexed: 12/11/2022]
Abstract
The purpose of this study is to investigate the molecular mechanisms and biological function of TGF-β-activated Smad1/5 in dental epithelium. Immunohistochemistry was used to detect the expressions of TGF-β signaling-related gene in mice molar germ. Primary dental epithelial cells were cultured and treated with TGF-β1 at a concentration of 0.5 or 5 ng/mL. Small molecular inhibitors, SB431542 and ML347, was used to inhibite ALK5 and ALK1/2, respectively. Small interfering RNA was used to knock down Smad1/5 or Smad2/3. The proliferation rate of cells was evaluated by EdU assay. In the basal layer of dental epithelial bud TGF-β1 and p-Smad1/5 were highly expressed, and in the interior of the epithelial bud TGF-β1 was lowly expressed, whereas p-Smad2/3 was highly expressed. In primary cultured dental epithelial cells, low concentration of TGF-β1 activated Smad2/3 but not Smad1/5, while high concentration of TGF-β1 was able to activate both Smad2/3 and Smad1/5. SB431542 but not ML347 was able to block the phosphorylation of Smad2/3 by TGF-β1. Either SB431542 or ML347 was able to block the phosphorylation of Smad1/5 by TGF-β1. EdU staining showed that high concentration of TGF-β1 promoted dental epithelial cell proliferation, which was reversed by silencing Smad1/5, whereas low concentration of TGF-β1 inhibited cell proliferation, which was reversed by silencing Smad2/3. In conclusions, TGF-β exhibits dual roles in the regulation of dental epithelial cell proliferation through two pathways. On the one hand, TGF-β activates canonical Smad2/3 signaling through ALK5, inhibiting the proliferation of internal dental epithelial cells. On the other hand, TGF-β activates noncanonical Smad1/5 signaling through ALK1/2-ALK5, promoting the proliferation of basal cells in the dental epithelial bud.
Collapse
Affiliation(s)
- Hao Zhang
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Luoyu Road #237, Hongshan District, Wuhan, 430079, Hubei, China
| | - Yunyan Zhan
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Luoyu Road #237, Hongshan District, Wuhan, 430079, Hubei, China
| | - Yue Zhang
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Luoyu Road #237, Hongshan District, Wuhan, 430079, Hubei, China
| | - Guohua Yuan
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Luoyu Road #237, Hongshan District, Wuhan, 430079, Hubei, China
| | - Guobin Yang
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Luoyu Road #237, Hongshan District, Wuhan, 430079, Hubei, China.
| |
Collapse
|
4
|
Liu Z, Chen T, Bai D, Tian W, Chen Y. Smad7 Regulates Dental Epithelial Proliferation during Tooth Development. J Dent Res 2019; 98:1376-1385. [PMID: 31499015 DOI: 10.1177/0022034519872487] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Tooth morphogenesis involves dynamic changes in shape and size as it proceeds through the bud, cap, and bell stages. This process requires exact regulation of cell proliferation and differentiation. Smad7, a general antagonist against transforming growth factor-β (TGF-β) signaling, is necessary for maintaining homeostasis and proper functionality in many organs. While TGF-β signaling is widely involved in tooth morphogenesis, the precise role of Smad7 in tooth development remains unknown. In this study, we showed that Smad7 is expressed in the developing mouse molars with a high level in the dental epithelium but a moderate to weak level in the dental mesenchyme. Smad7 deficiency led to a profound decrease in tooth size primarily due to a severely compromised cell proliferation capability in the dental epithelium. Consistent with the tooth shrinkage phenotype, RNA sequencing (RNA-seq) analysis revealed that Smad7 ablation downregulated genes referred to epithelial cell proliferation and cell cycle G1/S phase transition, whereas the upregulated genes were involved in responding to TGF-β signaling and cell cycle arrest. Among these genes, the expression of Cdkn1a (encoding p21), a negative cell proliferation regulator, was remarkably elevated in parallel with the diminution of Ccnd1 encoding the crucial cell cycle regulator cyclin D1 in the dental epithelium. Meanwhile, the expression level of p-Smad2/3 was ectopically elevated in the developing tooth germ of Smad7 null mice, indicating the hyperactivation of the canonical TGF-β signaling. These effects were reversed by addition of TGF-β signaling inhibitor in cell cultures of Smad7-/- molar tooth germs, with rescued expression of cyclin D1 and cell proliferation rate. In sum, our studies demonstrate that Smad7 functions primarily as a positive regulator of cell proliferation via inhibition of the canonical TGF-β signaling during dental epithelium development and highlight a crucial role for Smad7 in regulating tooth size.
Collapse
Affiliation(s)
- Z Liu
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Disease, West China Hospital of Stomatology, Sichuan University, Chengdu, P.R. China.,Department of Cell and Molecular Biology, Tulane University, New Orleans, LA, USA.,Department of Oral and Maxillofacial Surgery, West China Hospital of Stomatology, Sichuan University, Chengdu, P.R. China
| | - T Chen
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Disease, West China Hospital of Stomatology, Sichuan University, Chengdu, P.R. China.,Department of Cell and Molecular Biology, Tulane University, New Orleans, LA, USA.,Department of Orthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, P.R. China
| | - D Bai
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Disease, West China Hospital of Stomatology, Sichuan University, Chengdu, P.R. China.,Department of Orthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, P.R. China
| | - W Tian
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Disease, West China Hospital of Stomatology, Sichuan University, Chengdu, P.R. China.,Department of Oral and Maxillofacial Surgery, West China Hospital of Stomatology, Sichuan University, Chengdu, P.R. China
| | - Y Chen
- Department of Cell and Molecular Biology, Tulane University, New Orleans, LA, USA
| |
Collapse
|
5
|
Song W, Wang Y, Chu Q, Qi C, Gao Y, Gao Y, Xiang L, Zhenzhen X, Gao Y. Loss of transforming growth factor-β1 in epithelium cells affects enamel formation in mice. Arch Oral Biol 2018; 96:146-154. [PMID: 30243146 DOI: 10.1016/j.archoralbio.2018.09.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Revised: 09/07/2018] [Accepted: 09/08/2018] [Indexed: 01/23/2023]
Abstract
OBJECTIVES In order to understand the specific in vivo function of transforming growth factor-beta1 (TGF-β1), we successfully established aTGF-β1 deficient mouse model using a conditional knockout method. In the present study, we aimed to further understand the potential role of TGF-β1 in enamel formation. DESIGN Transgenic mice withoutTGF-β1 in epithelial cells were generated. Scanning electron microscopy and micro-computed tomography analysis were used to detect the dental appearance, enamel microstructure and tooth density. Histological analysis was used to examine the residual organic matrix of enamel. Quantitative real-time polymerase chain reaction was used to analyze the expressions of enamel matrix proteins at the mRNA level. RESULTS The enamel of mandibular molars and incisors inTGF-β1 conditional knockout mice displayed severe attrition and lower density compared with the wild-type littermates. A slender microstructure of enamel rod was observed, and enamel matrix proteins were retained in the enamel space at the maturation stage in conditional knockout mice. Moreover, the expressions of enamel matrix protein-encoding genes, such as amelogenin (Amelx), ameloblastin (Ambn), Enamelin (Enam) and matrix metalloproteinase-20 (Mmp-20), were increased in enamel organs of conditional knockout mice. On the other hand, the expressions of Amelotin (Amtn), kallikrein-related peptidase-4 (Klk4), C4orf26 and WD repeat-containing protein 72 (Wdr72) were dramatically decreased at the transition and maturation stages. CONCLUSIONS TGF-β1 played an important role in enamel mineralization through decreasing synthesis ofAmelx, Ambn and Enam and increasing synthesis of Klk4, Amtn, Corf26 and Wdr72.
Collapse
Affiliation(s)
- Wenying Song
- Department of Stomatology, Hospital Affiliated to Binzhou Medical University, Binzhou City, Shandong Province, 256603, People's Republic of China
| | - Yanli Wang
- Binzhou People's Hospital of Shandong Province, Shandong Binzhou 2566610, People's Republic of China
| | - Qing Chu
- Department of Stomatology, Hospital Affiliated to Binzhou Medical University, Binzhou City, Shandong Province, 256603, People's Republic of China
| | - Congcong Qi
- Institute of Stomatology, Binzhou Medical University, Yantai, Shandong Province 264003, People's Republic of China
| | - Yuehua Gao
- Institute of Stomatology, Binzhou Medical University, Yantai, Shandong Province 264003, People's Republic of China
| | - Yan Gao
- Department of Stomatology, Hospital Affiliated to Binzhou Medical University, Binzhou City, Shandong Province, 256603, People's Republic of China
| | - Lili Xiang
- Department of Stomatology, Hospital Affiliated to Binzhou Medical University, Binzhou City, Shandong Province, 256603, People's Republic of China
| | - Xu Zhenzhen
- Department of Stomatology, Hospital Affiliated to Binzhou Medical University, Binzhou City, Shandong Province, 256603, People's Republic of China
| | - Yuguang Gao
- Department of Stomatology, Hospital Affiliated to Binzhou Medical University, Binzhou City, Shandong Province, 256603, People's Republic of China.
| |
Collapse
|
6
|
Differential expression of transforming growth factor-beta1, connective tissue growth factor, phosphorylated-SMAD2/3 and phosphorylated-ERK1/2 during mouse tooth development. J Mol Histol 2017; 48:347-355. [PMID: 28825193 DOI: 10.1007/s10735-017-9733-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Accepted: 08/16/2017] [Indexed: 10/19/2022]
Abstract
Connective tissue growth factor (CTGF) is a downstream mediator of transforming growth factor-beta 1 (TGF-β1) and TGF-β1-induced CTGF expression is regulated through SMAD and mitogen-activated protein kinase (MAPK) signaling pathways. The fine modulation of TGF-β1 signaling is very important to the process of tooth development. However, little is known about the localization of CTGF, MAPK and SMAD in the context of TGF-β1 signaling during odontogenesis. Hence, we aimed to investigate the expression of TGF-β1, CTGF, phosphorylated-SMAD2/3 (p-SMAD2/3) and phosphorylated-ERK1/2 (p-ERK1/2). ICR mice heads of embryonic (E) day 13.5, E14.5, E16.5, postnatal (PN) day 0.5 and PN3.5 were processed for immunohistochemistry. Results revealed that at E13.5, TGF-β1 and CTGF were strongly expressed in dental epithelium (DE) and dental mesenchyme (DM), while p-SMAD2/3 was intensely expressed in the internal side of DE. p-ERK1/2 was not present in DE or DM. At E14.5 and E16.5, strong staining for TGF-β1 and CTGF was detected in enamel knot (EK) and dental papilla (DPL). DPL was intensely stained for p-ERK1/2 but negatively stained for p-SMAD2/3. There was no staining for p-SMAD2/3 and p-ERK1/2 in EK. At PN0.5 and PN3.5, moderate to intense staining for TGF-β1 and CTGF was evident in preameloblasts (PA), secretary ameloblasts (SA) and dental pulp (DP). p-SMAD2/3 was strongly expressed in SA and DP but sparsely localized in PA. p-ERK1/2 was intensely expressed in DP, although negative staining was observed in PA and SA. These data demonstrate that TGF-β1 and CTGF show an identical expression pattern, while p-SMAD2/3 and p-ERK1/2 exhibit differential expression, and indicate that p-SMAD2/3 and p-ERK1/2 might play a regulatory role in TGF-β1 induced CTGF expression during tooth development.
Collapse
|
7
|
Zhang Y, Wang S, Liu S, Li C, Wang J. Role of Smad signaling in kidney disease. Int Urol Nephrol 2015; 47:1965-75. [DOI: 10.1007/s11255-015-1115-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Accepted: 09/18/2015] [Indexed: 01/21/2023]
|
8
|
Li Q, Zhang D, Wang Y, Sun P, Hou X, Larner J, Xiong W, Mi J. MiR-21/Smad 7 signaling determines TGF-β1-induced CAF formation. Sci Rep 2014; 3:2038. [PMID: 23784029 PMCID: PMC3687228 DOI: 10.1038/srep02038] [Citation(s) in RCA: 143] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2013] [Accepted: 06/04/2013] [Indexed: 12/24/2022] Open
Abstract
How TGF-β1-mediated signaling pathways are finely tuned to orchestrate the generation of carcinoma-associated fibroblasts (CAFs) is poorly understood. Here, we demonstrate that miR-21 and the signaling of its target Smad 7 determine TGF-β1-induced CAF formation. In primary cultured fibroblasts, mature miR-21 increases after TGF-β1 treatment, whereas the Smad 7 protein level decreases. MiR-21 binds to the 3′ UTR of Smad7 mRNA and inhibits its translation, rather than causing its degradation. Most importantly, Smad 7 is bound to Smad 2 and 3, which are thought to competitively bind to TGFBR1, and prevents their activation upon TGF-β1 stimulation. The depletion of miR-21 or the overexpression of Smad 7 blocks TGF-β1-induced CAF formation, whereas the overexpression of miR-21 or the depletion of Smad 7 promotes CAF formation, even without TGF-β1 stimulation. Collectively, these findings clearly demonstrate that miR-21 and Smad7 are critical regulators of TGF-β1 signaling during the induction of CAF formation.
Collapse
Affiliation(s)
- Qiong Li
- Department of Biochemistry & Molecular Cell Biology, Shanghai Key Laboratory of Tumor Microenvironment and Inflammation, Shanghai Jiao Tong University School of Medicine
| | | | | | | | | | | | | | | |
Collapse
|
9
|
Poché RA, Sharma R, Garcia MD, Wada AM, Nolte MJ, Udan RS, Paik JH, DePinho RA, Bartlett JD, Dickinson ME. Transcription factor FoxO1 is essential for enamel biomineralization. PLoS One 2012; 7:e30357. [PMID: 22291941 PMCID: PMC3265481 DOI: 10.1371/journal.pone.0030357] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2011] [Accepted: 12/14/2011] [Indexed: 01/10/2023] Open
Abstract
The Transforming growth factor β (Tgf-β) pathway, by signaling via the activation of Smad transcription factors, induces the expression of many diverse downstream target genes thereby regulating a vast array of cellular events essential for proper development and homeostasis. In order for a specific cell type to properly interpret the Tgf-β signal and elicit a specific cellular response, cell-specific transcriptional co-factors often cooperate with the Smads to activate a discrete set of genes in the appropriate temporal and spatial manner. Here, via a conditional knockout approach, we show that mice mutant for Forkhead Box O transcription factor FoxO1 exhibit an enamel hypomaturation defect which phenocopies that of the Smad3 mutant mice. Furthermore, we determined that both the FoxO1 and Smad3 mutant teeth exhibit changes in the expression of similar cohort of genes encoding enamel matrix proteins required for proper enamel development. These data raise the possibility that FoxO1 and Smad3 act in concert to regulate a common repertoire of genes necessary for complete enamel maturation. This study is the first to define an essential role for the FoxO family of transcription factors in tooth development and provides a new molecular entry point which will allow researchers to delineate novel genetic pathways regulating the process of biomineralization which may also have significance for studies of human tooth diseases such as amelogenesis imperfecta.
Collapse
Affiliation(s)
- Ross A. Poché
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Ramaswamy Sharma
- Department of Cytokine Biology, Forsyth Institute, and Department of Developmental Biology, Harvard School of Dental Medicine, Cambridge, Massachusetts, United States of America
| | - Monica D. Garcia
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Aya M. Wada
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Mark J. Nolte
- Department of Genetics, University of Texas M. D. Anderson Cancer Center, Houston, Texas, United States of America
| | - Ryan S. Udan
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Ji-Hye Paik
- Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, New York, New York, United States of America
| | - Ronald A. DePinho
- Departments of Medical Oncology, Medicine, and Genetics, Belfer Institute for Applied Cancer Science, Dana-Farber Cancer Institute and Harvard Medical School, Boston, Massachusetts, United States of America
| | - John D. Bartlett
- Department of Cytokine Biology, Forsyth Institute, and Department of Developmental Biology, Harvard School of Dental Medicine, Cambridge, Massachusetts, United States of America
| | - Mary E. Dickinson
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas, United States of America
- Program in Developmental Biology, Baylor College of Medicine, Houston, Texas, United States of America
- * E-mail:
| |
Collapse
|
10
|
Expression patterns of histone acetyltransferases p300 and CBP during murine tooth development. In Vitro Cell Dev Biol Anim 2011; 48:61-8. [DOI: 10.1007/s11626-011-9472-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2011] [Accepted: 11/10/2011] [Indexed: 01/24/2023]
|
11
|
Moriguchi M, Yamada M, Miake Y, Yanagisawa T. Immunolocalization of TAK1, TAB1, and p38 in the developing rat molar. Anat Sci Int 2010; 86:69-77. [PMID: 20730577 DOI: 10.1007/s12565-010-0089-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2009] [Accepted: 06/30/2010] [Indexed: 01/23/2023]
Abstract
In tooth development, transforming growth factor beta (TGF-β) and bone morphogenetic protein (BMP) are involved in cell differentiation and matrix protein production. TGF-β and BMP have two signaling pathways: the Smad pathway and the non-Smad pathway. However, only a few studies have focused on the non-Smad pathway in tooth development. TGF-β-activated kinase 1 (TAK1) is activated by TGF-β or BMP and binds to TAK1-binding protein (TAB1), activating p38 or c-Jun N-terminal kinase (JNK), forming the non-Smad signaling pathway. In this study, we examined the distribution of these kinases, TGF-β receptor 1 (TGF-β-R1), BMP receptor-1B (BMPR-1B) and Smad4 in cells of the rat molar germ histochemically, in order to investigate the signaling pathway in each type of cell. Immunostaining for TGF-β-R1, BMPR-1B, Smad4, TAK1, TAB1 and phosphorylated-p38 (p-p38) showed similar reactions. In the cervical loop, reactions were clearer than in other enamel epithelium. In the inner enamel epithelium, signal increased with differentiation into ameloblasts, became strongest in the secretory stage, and decreased rapidly in the maturation stage. Signal also increased upon differentiation from preodontoblasts to odontoblasts. In Hertwig's epithelial sheath, with the exception of BMPR-1B, reactions were stronger in the later stage, showing more enamel protein secretion than in the early stage. However, no clear reaction corresponding to phosphorylated-JNK was observed in any type of cell. These results suggest that TGF-β or BMP is involved in the induction of differentiation of inner enamel epithelium cells into ameloblasts, and preodontoblast differentiation into odontoblasts, the regulation of cervical loop cell proliferation, the elongation or regulation of the epithelial sheath, and the secretion of enamel protein and dentin matrix protein through the non-Smad signaling pathway via TAK1, TAB1 and p38 as well as Smad signaling pathways in the rat molar germ.
Collapse
Affiliation(s)
- Mitsuko Moriguchi
- Department of Ultrastructural Science, Tokyo Dental College, 1-2-2 Masago, Mihama-ku, Chiba, 261-8502, Japan.
| | | | | | | |
Collapse
|
12
|
Pacheco MS, Reis AH, Aguiar DP, Lyons KM, Abreu JG. Dynamic analysis of the expression of the TGFbeta/SMAD2 pathway and CCN2/CTGF during early steps of tooth development. Cells Tissues Organs 2007; 187:199-210. [PMID: 18089935 DOI: 10.1159/000112640] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/30/2007] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIMS CCN2 is present during tooth development. However, the relationship between CCN2 and the transforming growth factor beta (TGFbeta)/SMAD2/3 signaling cascade during early stages of tooth development is unclear. Here, we compare the expression of CCN2 and TGFbeta/SMAD2/3 components during tooth development, and analyze the functioning of TGFbeta/SMAD2/3 in wild-type (WT) and Ccn2 null (Ccn2-/-) mice. METHODS Coronal sections of mice on embryonic day (E)11.5, E12.5, E13.5, E14.5 and E18.5 from WT and Ccn2-/- were immunoreacted to detect CCN2 and components of the TGFbeta signaling pathway and assayed for 5'-bromo-2'-deoxyuridine immunolabeling and proliferating cell nuclear antigen immunostaining. RESULTS CCN2 and TGFbeta signaling components such as TGFbeta1, TGFbeta receptor II, SMADs2/3 and SMAD4 were expressed in inducer tissues during early stages of tooth development. Proliferation analysis in these areas showed that epithelial cells proliferate less than mesenchymal cells from E11.5 to E13.5, while at E14.5 they proliferate more than mesenchymal cells. We did not find a correlation between functioning of the TGFbeta1 cascade and CCN2 expression because Ccn2-/- mice showed neither a reduction in SMAD2 phosphorylation nor a difference in cell proliferation. CONCLUSION CCN2 and the TGFbeta/SMAD2/3 signaling pathway are active in signaling centers of tooth development where proliferation is dynamic, but these mechanisms may act independently.
Collapse
Affiliation(s)
- Marcos S Pacheco
- Departamento de Anatomia, Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | | | | | | | | |
Collapse
|
13
|
Klopcic B, Maass T, Meyer E, Lehr HA, Metzger D, Chambon P, Mann A, Blessing M. TGF-β superfamily signaling is essential for tooth and hair morphogenesis and differentiation. Eur J Cell Biol 2007; 86:781-99. [PMID: 17499880 DOI: 10.1016/j.ejcb.2007.03.005] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2006] [Revised: 03/09/2007] [Accepted: 03/09/2007] [Indexed: 12/22/2022] Open
Abstract
Members of the transforming growth factor beta (TGF-beta) superfamily of signaling molecules are involved in the regulation of many developmental processes that involve the interaction between mesenchymal and epithelial tissues. Smad7 is a potent inhibitor of many members of the TGF-beta family, notably TGF-beta and activin. In this study, we show that embryonic overexpression of Smad7 in stratified epithelia using a keratin 5 promoter, results in severe morphogenetic defects in skin and teeth and leads to embryonic and perinatal lethality. To further analyze the functions of Smad7 in epithelial tissues of adult mice, we used an expression system that allowed a controlled overexpression of Smad7 in terms of both space and time. Skin defects in adult mice overexpressing Smad7 were characterized by hyper-proliferation and missing expression of early markers of keratinocyte differentiation. Upon Smad7-mediated blockade of TGF-beta superfamily signaling, ameloblasts failed to produce an enamel layer in incisor teeth. In addition, TGF-beta blockade in adult mice altered the pattern of thymic T cell differentiation and the number of thymic T cells was significantly reduced. This study shows that TGF-beta superfamily signaling is essential for development of hair, tooth and T-cells as well as differentiation and proliferation control in adult tissues.
Collapse
Affiliation(s)
- Borut Klopcic
- I. Medical Department, Section Pathophysiology, Johannes Gutenberg University, Mainz, Germany
| | | | | | | | | | | | | | | |
Collapse
|
14
|
Zhang YD, Chen Z, Song YQ, Liu C, Chen YP. Making a tooth: growth factors, transcription factors, and stem cells. Cell Res 2007; 15:301-16. [PMID: 15916718 DOI: 10.1038/sj.cr.7290299] [Citation(s) in RCA: 204] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Mammalian tooth development is largely dependent on sequential and reciprocal epithelial-mesenchymal interactions. These processes involve a series of inductive and permissive interactions that result in the determination, differentiation, and organization of odontogenic tissues. Multiple signaling molecules, including BMPs, FGFs, Shh, and Wnt proteins, have been implicated in mediating these tissue interactions. Transcription factors participate in epithelial-mesenchymal interactions via linking the signaling loops between tissue layers by responding to inductive signals and regulating the expression of other signaling molecules. Adult stem cells are highly plastic and multipotent. These cells including dental pulp stem cells and bone marrow stromal cells could be reprogrammed into odontogenic fate and participated in tooth formation. Recent progress in the studies of molecular basis of tooth development, adult stem cell biology, and regeneration will provide fundamental knowledge for the realization of human tooth regeneration in the near future.
Collapse
|
15
|
Gebeshuber CA, Sladecek S, Grunert S. Beta-catenin/LEF-1 signalling in breast cancer--central players activated by a plethora of inputs. Cells Tissues Organs 2007; 185:51-60. [PMID: 17587808 DOI: 10.1159/000101303] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Although the role of Wnt signalling in breast cancer is far from being fully understood, in the last years its importance has been reported frequently. Besides stimulation by canonical Wnt signalling, the downstream effectors beta-catenin and the transcriptional modulators of the T-cell factor/lymphoid enhancer-binding factor (TCF/LEF) family can also be activated by other inputs including the TGF-beta pathway. Wnt and TGF-beta signalling are both major signal transduction pathways, which provide important cues during development and tumor progression. However, particularly TGF-beta has a complicated influence on oncogenesis, which ranges from suppressive to promoting activity. Signalling pathways activated in parallel with TGF-beta might determine the oncogenic influence, and therefore place signals cooperating with TGF-beta into the limelight. During early development Wnt and TGF-beta signalling collaborate extensively. Here we provide an overview of the known interactions of Wnt with TGF-beta signalling in development and metastasis, particularly in breast cancer. We want to focus on the Wnt-activated transcription factor complex beta-catenin/LEF-1, its upstream activators, its downstream targets and consequences on the cellular level in response to beta-catenin/LEF-1 activation.
Collapse
|
16
|
Iamaroon A, Pattamapun K, Piboonniyom SO. Aberrant expression of Smad4, a TGF-beta signaling molecule, in oral squamous cell carcinoma. J Oral Sci 2007; 48:105-9. [PMID: 17023741 DOI: 10.2334/josnusd.48.105] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
Although carcinogenesis of oral squamous cell carcinoma (OSCC) has been studied by many investigators in the past decade, the available evidence about its molecular mechanism is inconclusive. The objective of the present study was to compare expression of Smad4, a signaling molecule of the transforming growth factor beta (TGF-beta) pathway, between OSCC and normal oral mucosa. We assayed expression of Smad4 in OSCC and normal oral mucosa by performing immunohistochemistry using paraffin-embedded tissue samples. We also compared expression of Smad4 protein between OSCC lines and normal oral keratinocytes, using Western blot analysis. Smad4 expression was observed in only 60% of OSCC tissue samples, whereas it was observed in 82% of normal oral mucosa samples. Reduced Smad4 expression was clearly observed in all OSCC lines, compared with normal oral keratinocytes. These findings suggest that aberration of the TGF-beta pathway, as indicated by a reduction or absence of Smad4 expression, promotes carcinogenesis of OSCC.
Collapse
Affiliation(s)
- Anak Iamaroon
- Department of Odontology and Oral Pathology, Faculty of Dentistry, Chiang Mai University, Thailand.
| | | | | |
Collapse
|
17
|
Inamoto S, Iwata S, Inamoto T, Nomura S, Sasaki T, Urasaki Y, Hosono O, Kawasaki H, Tanaka H, Dang NH, Morimoto C. Crk-associated substrate lymphocyte type regulates transforming growth factor-beta signaling by inhibiting Smad6 and Smad7. Oncogene 2006; 26:893-904. [PMID: 16909115 DOI: 10.1038/sj.onc.1209848] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Crk-associated substrate lymphocyte type (Cas-L) is a 105 kDa docking protein with diverse functional properties, including regulation of cell division, proliferation, migration and adhesion. Cas-L is also involved in beta1 integrin- or antigen receptor-mediated signaling in B and T cells. In the present study, we demonstrate that Cas-L potentiates transforming growth factor-beta (TGF-beta) signaling pathway by interacting with Smad6 and Smad7. Immunoprecipitation experiments reveal that single domain deletion of full-length Cas-L completely abolishes its docking function with Smad6 and Smad7, suggesting that the natural structure of Cas-L is necessary for its association with Smad6 and Smad7. On the other hand, both N-terminal and C-terminal deletion mutants of Smad6 and Smad7 still retain their docking ability to Cas-L, suggesting that Smad6 and Smad7 possess several binding motifs to Cas-L. Moreover, Cas-L interaction with Mad-homology (MH)2 domain, but not with MH1 domain of Smad6 or Smad7, ameliorates TGF-beta-induced signaling pathway. Finally, depletion of Cas-L by small-interfering RNA oligo attenuates TGF-beta-induced growth inhibition of Huh-7 cells, with a concomitant reduction in phosphorylation of Smad2 and Smad3. These results strongly suggest that Cas-L is a potential regulator of TGF-beta signaling pathway.
Collapse
Affiliation(s)
- S Inamoto
- Division of Clinical Immunology, Advanced Clinical Research Center, Institute of Medical Science, The University of Tokyo, Tokyo, Japan
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Luukko K, Kvinnsland IH, Kettunen P. Tissue interactions in the regulation of axon pathfinding during tooth morphogenesis. Dev Dyn 2006; 234:482-8. [PMID: 16217735 DOI: 10.1002/dvdy.20586] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Like many other organs, the tooth develops as a result of the epithelial-mesenchymal interactions. In addition, the tooth is a well-defined peripheral target organ for sensory trigeminal nerves, which are required for the function and protection of the teeth. Dental trigeminal axon growth and patterning are tightly linked with advancing tooth morphogenesis and cell differentiation. This review summarizes recent findings on the regulation of dental axon pathfinding, which have provided evidence that the development of tooth trigeminal innervation is controlled by epithelial-mesenchymal interactions. The early dental epithelium possesses the information to instruct tooth nerve supply, and signals mediating these interactions are part of the signaling networks regulating tooth morphogenesis. Tissue interactions, thus, appear to provide a central mechanism of spatiotemporally orchestrating tooth formation and dental axon navigation and patterning.
Collapse
Affiliation(s)
- Keijo Luukko
- Section of Anatomy and Cell Biology, Department of Biomedicine, University of Bergen, Bergen, Norway. keijo.luukko.@pki.uib.no
| | | | | |
Collapse
|
19
|
Behnan SM, Guo C, Gong TW, Shum L, Gong SG. Gene and protein expression of transforming growth factor beta 2 gene during murine primary palatogenesis. Differentiation 2005; 73:233-9. [PMID: 16026545 DOI: 10.1111/j.1432-0436.2005.00022.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The molecular mechanisms by which the primordia of the midface grow and fuse to form the primary palate are not well characterized. This is in spite of the fact that failure of growth and/or fusion of these facial primordia leads to the common human craniofacial birth defects, clefts of the lip with or without clefts of the palate. Members of the transforming growth factor beta (Tgfbeta) superfamily have been shown to play critical roles during craniofacial development. Specifically, the role of Tgfbeta-3 in mediating the fusion of the embryonic secondary palatal shelves is well documented. In a screen for genes expressed during fusion of the murine midfacial processes, Tgfbeta2 was identified as a gene differentially expressed during fusion of the lateral and medial nasal processes. The objective of our study was to analyze the spatial and temporal expression of Tgfbeta2 during critical stages of midfacial morphogenesis at both the transcript and protein levels. We also compared the pattern of expression of Tgfbeta2 with that of Bmp4, a gene shown previously to be involved in mediating the fusion process in the midface. Our results showed Tgfbeta2 expression in a very restrictive area of the epithelial layer along the borders of the midfacial primordia, in a pattern very similar to that of Bmp4. The highly restrictive and spatial and temporal pattern of expression of Tgfbeta2 implicates its role in mediating the fusion of the midfacial processes, possibly through interacting with Bmp4 in the regulation of apoptosis and/or epithelial-mesenchymal transformation. A greater understanding of the role of this gene will clarify how the normal midface grows and the mechanisms behind cleft development.
Collapse
Affiliation(s)
- Scott M Behnan
- School of Dentistry, University of Michigan, 1011 N. University Avenue, Ann Arbor, MI 48109-1078, USA
| | | | | | | | | |
Collapse
|
20
|
Sista AK, O'Connell MK, Hinohara T, Oommen SS, Fenster BE, Glassford AJ, Schwartz EA, Taylor CA, Reaven GM, Tsao PS. Increased aortic stiffness in the insulin-resistant Zuckerfa/farat. Am J Physiol Heart Circ Physiol 2005; 289:H845-51. [PMID: 15833807 DOI: 10.1152/ajpheart.00134.2005] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Accumulating clinical evidence indicates increased aortic stiffness, an independent risk factor for cardiovascular and all-cause mortality, in type 2 diabetic and glucose-intolerant individuals. The present study sought to determine whether increased mechanical stiffness, an altered extracellular matrix, and a profibrotic gene expression profile could be observed in the aorta of the insulin-resistant Zucker fa/fa rat. Mechanical testing of Zucker fa/fa aortas showed increased vascular stiffness in longitudinal and circumferential directions compared with Zucker lean controls. Unequal elevations in developed strain favoring the longitudinal direction resulted in a loss of anisotropy. Real-time quantitative PCR and immunohistochemistry revealed increased expression of fibronectin and collagen IVα3in the Zucker fa/fa aorta. In addition, expression of transforming growth factor-β and several Smad proteins was increased in vessels from insulin-resistant animals. In rat vascular smooth muscle cells, 12–18 h of exposure to insulin (100 nmol/l) enhanced transforming growth factor-β1 mRNA expression, implicating a role for hyperinsulinemia in vascular stiffness. Thus there is mechanical, structural, and molecular evidence of arteriosclerosis in the Zucker fa/fa rat at the glucose-intolerant, hyperinsulinemic stage.
Collapse
Affiliation(s)
- Akhilesh K Sista
- Division of Cardiovascular Sciences, Dept. of Cardiovascular Medicine, Stanford School of Medicine, 300 Pasteur Dr., Stanford, CA 94305, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
21
|
Chen S, Rani S, Wu Y, Unterbrink A, Gu TT, Gluhak-Heinrich J, Chuang HH, Macdougall M. Differential regulation of dentin sialophosphoprotein expression by Runx2 during odontoblast cytodifferentiation. J Biol Chem 2005; 280:29717-27. [PMID: 15980071 DOI: 10.1074/jbc.m502929200] [Citation(s) in RCA: 127] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Dentin sialophosphoprotein (DSPP) consists of dentin sialoprotein (DSP) and dentin phosphoprotein (DPP). The spatial-temporal expression of DSPP is largely restricted during differentiational stages of dental cells. DSPP plays a vital role in tooth development. It is known that an osteoblast-specific transcription factor, Runx2, is essential for osteoblast differentiation. However, effects of Runx2 on DSPP transcription remain unknown. Here, we studied different roles of Runx2 in controlling DSPP expression in mouse preodontoblast (MD10-F2) and odontoblast (MO6-G3) cells. Two Runx2 isoforms were expressed in preodontoblast and odontoblast cells, and in situ hybridization assay showed that DSPP expression increased, whereas Runx2 was down-regulated during odontoblast differentiation and maturation. Three potential Runx2 sites are present in promoters of mouse and rat DSPP genes. Runx2 binds to these sites as demonstrated by electrophoretic mobility shift assay and supershift experiments. Mutations of Runx2 sites in mouse DSPP promoter resulted in a decline of promoter activity in MD10-F2 cells compared with an increase of its activity in MO6-G3 cells. Multiple Runx2 sites were more active than a single site in regulating the DSPP promoter. Furthermore, forced overexpression of Runx2 isoforms induced increases of endogenous DSPP protein levels in MD10-F2 cells but reduced its expression in MO6-G3 cells consistent with the DSPP promoter analysis. Thus, our results suggest that differential positive and negative regulation of DSPP by Runx2 is dependent on use of cytodifferentiation of dental ectomesenchymal-derived cells that may contribute to the spatial-temporal expression of DSPP during tooth development.
Collapse
Affiliation(s)
- Shuo Chen
- Department of Pediatric Dentistry, The University of Texas Health Science Center, San Antonio, 78229-3900, USA.
| | | | | | | | | | | | | | | |
Collapse
|
22
|
He WX, Niu ZY, Zhao SL, Jin WL, Gao J, Smith AJ. TGF-β activated Smad signalling leads to a Smad3-mediated down-regulation of DSPP in an odontoblast cell line. Arch Oral Biol 2004; 49:911-8. [PMID: 15353247 DOI: 10.1016/j.archoralbio.2004.05.005] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/11/2004] [Indexed: 11/15/2022]
Abstract
OBJECTIVE Transforming growth factor-beta (TGF-beta) regulates odontoblast differentiation and stimulates dentine extracellular matrix synthesis. However, until recently, the molecular mechanisms of action of TGF-beta have been unknown. Smad proteins have recently been identified as intracellular signalling mediators of TGF-beta. In this study, we characterise the role of Smad proteins as mediators of TGF-beta in a mouse odontoblast cell line MDPC-23. METHODS Transcription of Smads was detected by RT-PCR. The change of intracellular location of Smad proteins treated by TGF-beta1 was evaluated immunocytochemically. Smad function and its role in transcription of dentin sialophosphoprotein (DSPP) were investigated in cotransfection experiments using promoter-luciferase reporter gene constructs. RESULTS MDPC-23 cells expressed Smad2, Smad3 and Smad4 mRNA. Endogenous Smad2, Smad3 and Smad4 rapidly translocated from the cytoplasm into the nucleus in response to TGF-beta1. The activity of the TGF-beta-responsive p3TP-Lux reporter construct was stimulated by 12.7-fold with TGF-beta1 treatment. Over-expression of wild-type Smad3 promoted TGF-beta1-induced luciferase activity, whereas dominant negative Smad3 inhibited it. TGF-beta1 also inhibited the activity of DSPP promoter luciferase reporter construct containing the sequence between -791 bp and +54 bp of the mouse DSPP gene. Over-expression of wild-type Smad3 potentiate the inhibitory effect of TGF-beta1 on transcriptional regulation of DSPP, while dominant negative Smad3 decreased the effect. In contrast to Smad3, wild-type Smad2 or its dominant negative mutant had little effect on TGF-beta1 regulation of the promoter activity of DSPP. CONCLUSIONS Smad2, Smad3 and Smad4 are present and activated by TGF-beta1 in MDPC-23 cells. The Smad pathway is functional in these cells and Smad3 appears to be involved in down-regulation of DSPP by TGF-beta1. These findings raise the possibility that Smad signalling plays a role in dentinogenesis.
Collapse
Affiliation(s)
- Wen-Xi He
- Department of Operative Dentistry, Qin Du Stomatological Hospital, Xi'an, 710032, PR China.
| | | | | | | | | | | |
Collapse
|
23
|
Peterková R, Peterka M, Lesot H. The developing mouse dentition: a new tool for apoptosis study. Ann N Y Acad Sci 2004; 1010:453-66. [PMID: 15033770 DOI: 10.1196/annals.1299.083] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Developing limb or differentiating neural and blood cells are traditional models used to study programmed cell death in mammals. The developing mouse dentition can also be an attractive model for studying apoptosis regulation. Apoptosis is most extant during early odontogenesis in mice. The embryonic tooth pattern is comprised not only of anlagen of functional teeth (incisor, molars), but also of vestiges of ancestral tooth primordia that must be suppressed. Apoptosis is involved in (a) the elimination of vestigial tooth primordia in the prospective toothless gap (diastema) between the incisor and molars and (b) the shaping of germs in functional teeth. This type of apoptosis occurs in the dental epithelium according to a characteristic temporo-spatial pattern. Where apoptosis concentrates, specific signaling is also found. We proposed a hypothesis to explain the stimulation of apoptosis in the dental epithelium by integrating two concepts: (1) The regulation of epithelial budding by positional information generated from interactions between growth-activating and growth-inhibiting signals, and (2) apoptosis stimulation by the failure of death-suppressing signals. During the budding of the dental epithelium, local excess in growth inhibitors (e.g., Bmps) might lead to the epithelial cells' failure to receive adequate growth-activating (apoptosis-suppressing) signals (e.g., Fgfs). The resulting signal imbalance leads to cell "suicide" by apoptosis. Understanding of apoptosis regulation in the vestigial tooth primordia can help to elucidate the mechanism of their suppression during evolution and to identify factors essential for tooth survival. The latter knowledge will be important for developing a technology of tooth engineering.
Collapse
Affiliation(s)
- Renata Peterková
- Institute of Experimental Medicine, Academy of Sciences CR, Videnska 1083, 142 20 Prague 4, Czech Republic.
| | | | | |
Collapse
|
24
|
Pisano MM, Mukhopadhyay P, Greene RM. Molecular fingerprinting of TGFß-treated embryonic maxillary mesenchymal cells. Orthod Craniofac Res 2003; 6:194-209. [PMID: 14606523 DOI: 10.1034/j.1600-0544.2003.00264.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The transforming growth factor-beta (TGF(beta)) family represents a class of signaling molecules that plays a central role in normal embryonic development, specifically in development of the craniofacial region. Members of this family are vital to development of the secondary palate where they regulate maxillary and palate mesenchymal cell proliferation and extracellular matrix synthesis. The function of this growth factor family is particularly critical in that perturbation of either process results in a cleft of the palate. While the cellular and phenotypic effects of TGF(beta) on embryonic craniofacial tissue have been extensively cataloged, the specific genes that function as downstream mediators of TGF(beta) in maxillary/palatal development are poorly defined. Gene expression arrays offer the ability to conduct a rapid, simultaneous assessment of hundreds to thousands of differentially expressed genes in a single study. Inasmuch as the downstream sequelae of TGF(beta) action are only partially defined, a complementary DNA (cDNA) expression array technology (Clontech's Atlas Mouse cDNA Expression Arrays), was utilized to delineate a profile of differentially expressed genes from TGF(beta)-treated primary cultures of murine embryonic maxillary mesenchymal cells. Hybridization of a membrane-based cDNA array (1178 genes) was performed with 32P-labeled cDNA probes synthesized from RNA isolated from either TGF(beta)-treated or vehicle-treated embryonic maxillary mesenchymal cells. Resultant phosphorimages were subject to AtlasImage analysis in order to determine differences in gene expression between control and TGF(beta)-treated maxillary mesenchymal cells. Of the 1178 arrayed genes, 552 (47%) demonstrated detectable levels of expression. Steady state levels of 22 genes were up-regulated, while those of 8 other genes were down-regulated, by a factor of twofold or greater in response to TGF(beta). Affected genes could be grouped into three general functional categories: transcription factors and general DNA-binding proteins; growth factors/signaling molecules; and extracellular matrix and related proteins. The extent of hybridization of each gene was evaluated by comparison with the abundant, constitutively expressed mRNAs: ubiquitin, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), ornithine decarboxylase (ODC), cytoplasmic beta-actin and 40S ribosomal protein. No detectable changes were observed in the expression levels of these genes in-response to TGF(beta) treatment. Gene expression profiling results were verified by Real-Time quantitative polymerase chain reaction. Utilization of cDNA microarray technology has enabled us to delineate a preliminary transcriptional map of TGF(beta) responsiveness in embryonic maxillary mesenchymal cells. The profile of differentially expressed genes offers revealing insights into potential molecular regulatory mechanisms employed by TGF(beta) in orchestrating craniofacial ontogeny.
Collapse
Affiliation(s)
- M M Pisano
- Department of Molecular, Cellular and Craniofacial Biology, ULSD University of Louisville Birth Defects Center, Louisville, KY 40292, USA.
| | | | | |
Collapse
|
25
|
Yokozeki M, Afanador E, Nishi M, Kaneko K, Shimokawa H, Yokote K, Deng C, Tsuchida K, Sugino H, Moriyama K. Smad3 is required for enamel biomineralization. Biochem Biophys Res Commun 2003; 305:684-90. [PMID: 12763048 DOI: 10.1016/s0006-291x(03)00806-4] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Smad3 is an intracellular signaling molecule that mediates the signal from transforming growth factor-beta (TGF-beta) and activin receptors. In this study, we reveal hypomineralized enamel in mice with the targeted deletion of the Smad3 gene. The Smad3 (-/-) mice had chalky white incisor enamel, while the enamel of the wild-type or Smad3 (+/-) mice was yellow-brown. Histological analysis of the undecalcified sections showed that the enamel thickness of the maxillary incisors in the Smad3 (-/-) mice was similar to that of the wild-type and Smad3 (+/-) mice while that the enamel of the maxillary molars in Smad3 (-/-) mice was disrupted in places. Microcomputed tomography (microCT) analysis revealed that the mineralization of the maxillary incisors and mandibular molars in the Smad3 (-/-) mice showed significant reduction in the degree of mineralization when compared to that of the wild-type and Smad3 (+/-) mice. Scanning electron microscopic (SEM) analysis of the mandibular incisors revealed that the enamel surface of the Smad3 (-/-) mice was irregular and disrupted in places and showed images similar to decalcified mature enamel. The histological analysis of the decalcified sections showed that distinct morphological changes in the ameloblasts at the secretory and maturational stages were not observed between the Smad3 (-/-) and Smad3 (+/-) or wild-type mice, while the enamel matrix was observed in the decalcified sections of the mandibular molars in the Smad3 (-/-) mice. These results suggested that Smad3 was required for enamel biomineralization, and TGF-beta and activin signaling might be critical for its process.
Collapse
Affiliation(s)
- Masahiko Yokozeki
- Department of Orthodontics, School of Dentistry, The University of Tokushima, 3-18-15 Kuramoto-cho, Tokushima 770-8504, Japan
| | | | | | | | | | | | | | | | | | | |
Collapse
|
26
|
Chai Y, Ito Y, Han J. TGF-beta signaling and its functional significance in regulating the fate of cranial neural crest cells. CRITICAL REVIEWS IN ORAL BIOLOGY AND MEDICINE : AN OFFICIAL PUBLICATION OF THE AMERICAN ASSOCIATION OF ORAL BIOLOGISTS 2003; 14:78-88. [PMID: 12764071 DOI: 10.1177/154411130301400202] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Members of the transforming growth factor-beta (TGF-beta) superfamily regulate cell proliferation, differentiation, and apoptosis, and control the development and maintenance of most tissues. TGF-beta signal is transmitted through the phosphorylation of Smad proteins by TGF-beta receptor serine/threonine kinase. During craniofacial development, TGF-beta may regulate the fate specification of cranial neural crest cells. These cells are multipotent progenitors and capable of producing diverse cell types upon differentiation. Here we summarize evidence that TGF-beta ligands and their signaling intermediates have significant roles in patterning and specification of cranial neural crest cells. The biological function of TGF-beta is carried out through the regulation of transcriptional factors during embryogenesis.
Collapse
Affiliation(s)
- Y Chai
- Center for Craniofacial Molecular Biology, School of Dentistry, University of Southern California, 2250 Alcazar Street, CSA 103, Los Angeles, CA 90033, USA.
| | | | | |
Collapse
|
27
|
Soto P, Price-Schiavi SA, Carraway KL. SMAD2 and SMAD7 involvement in the post-translational regulation of Muc4 via the transforming growth factor-beta and interferon-gamma pathways in rat mammary epithelial cells. J Biol Chem 2003; 278:20338-44. [PMID: 12668667 DOI: 10.1074/jbc.m301886200] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Muc4/sialomucin complex (SMC) is a heterodimeric glycoprotein complex derived from a single gene that is post-translationally processed into mucin (ASGP-1) and transmembrane (ASGP-2) subunits. Muc4/SMC is tightly regulated in the rat mammary gland, low in the virgin, increased during pregnancy and lactation, and overexpressed in some aggressive mammary tumors. Investigations of primary rat mammary epithelial cells (MEC) have shown that Muc4/SMC expression is post-translationally regulated through inhibition of Muc4/SMC precursor processing by transforming growth factor-beta (TGF-beta). Localization studies suggest that TGF-beta inhibition of Muc4/SMC expression is mediated through SMAD2, a TGF-beta effector that, when activated, functions as a transcription factor. SMAD2 antisense oligonucleotide blocks the inhibition of Muc4/SMC expression by TGF-beta. The TGF-beta effect on Muc4/SMC expression is repressed by interferon-gamma (IFN-gamma). IFN-gamma treatment of MEC activates and relocalizes signal transducer and activator of transcription-1 (STAT-1) to induce an inhibitor SMAD, SMAD7. SMAD7 antisense oligonucleotide prevents IFN-gamma from blocking the TGF-beta inhibition of Muc4/SMC expression. These results suggest that TGF-beta regulates Muc4/SMC expression via the SMAD pathway by a transcriptional effect on a protein in the Muc4/SMC processing step, possibly the protease that cleaves the precursor.
Collapse
Affiliation(s)
- Pedro Soto
- Department of Biochemistry and Molecular Biology, University of Miami School of Medicine, Florida 33101, USA
| | | | | |
Collapse
|